Lighting fixture hanger



April 19, 1960 G. F. THOMAS 2,933,279

LIGHTING FIXTURE HANGER Filed Sept. 22, 1958 2 Sheets-Sheet 1 .33 7 36 Z27 2a 3/\ 34 324 26 2a 27 za FIG. 2

INVENTOR.

GAL E 72/0/1445 Br H/S ATTORNEYS HARE/.5; Knee/1, F0s7e& HARE/5 April19, 1960 G. F. THOMAS LIGHTING FIXTURE HANGER 2 Sheets-Sheet 2 FiledSept. 22, 1958 INVENTOR. GA LE Two/was 5r HA5 ATTORNEYS HARRIS; K150455752 & lime/s United States Patent LIGHTING FIXTURE HANGER Gale F.Thomas, Inglewood, CaliL, assignor to Smoot- Holman Company, Inglewood,Califi, a corporation of California Application September 22, 1958,Serial No. 762,594

Claims. (Cl. 248317) This invention relates to lighting fixtures hungfrom a ceiling, or other overhead structures, and in particular to afixture hanger including means for leveling and stabilizing the fixtureagainst vibration or shock.

Lighting fixtures, especially the fluorescent type, present aninstallation problem when hung from a sloping or uneven ceiling, forexample. The fixtures available are rigidly built to be hung from ahorizontal surface and cannot be leveled or aligned without modifying byshortening or bending parts of the fixture at considerable inconveniencewhile installing the same. Furthermore some available fixtures are notsuitably stabilized against vibration in that they are relatively freeswinging and can build up large amplitudes of swing due to resonancebecause they do not ofier increasing resistance to swinging as the angleof swing increases. Also, some available fixtures are so rigidlyconstructed that they do not suitably absorb shocks caused by thepassage of heavy vehicles or by earthquakes. This may result infracturing fragile parts of the fixture such as lenses, reflectors,lamps, etc.

Accordingly, it is an important object of my invention to provide ahanger for a lighting fixture which is free of all of theabove-described disadvantages and defects.

Another object of my invention is to provide a hanger for a lightingfixture which includes means for rapidly and conveniently leveling andaligning the fixture even when hung from sloping or uneven structuralsurfaces. A further object is to provide such a hanger which isstabilized against excessive swinging but also will ab sorb suddenstrong vibrations and shock without injury to fragile parts of thefixture. 1

Additional objects will become apparent from the following descriptionwhich is given primarily for reasons of illustration and not limitation.

Stated in general terms, the objects of my invention are attained byattaching the support bars of the fixture, such as the vertical supportbars, to a resilient member, preferably a resilient torsion member,which, in turn is attached rigidly to the fixture structure proper. Thetorsion bar is made of resilient material, such as a spring steel, andis dimensioned and shaped relative to the fixture to absorb vibrationand shock waves transmitted through the support bars. Also, the torsionbar is adapted to increase its stabilizing reaction as the action of thevibration or shock waves tends to increase the degree of sway or swingof the fixture. In addition, the frame of the fixture adjacent thetorsion bar is provided with adjustment means adapted to bear on thetorsion bar with controlled degree of force to conveniently level oralign the fixture by slightly displacing the position of the fixtureproper relative to the positions of the support bars.

A more detailed description of a specific embodiment of my invention isgiven below with reference to the attached drawings, wherein:

Fig. 1 is a partial isometric view of an assemblyconsisting of an endframe member or stabilizer containing 2,933,279 Patented Apr. 19, 1960 ra torsion bar to which is attached a vertical support member;

Fig. 2 is a partial sectional elevational view taken along the line 2--2of Fig. l and drawn to an enlarged scale;

Fig. 3 is a partial isometric view showing a torsion bar and a nutattached at the middle thereof;

Fig. 4 is a perspective view showing two fixture units combined inend-to-end relationship;

Fig. 5 is a partial plan view showing an end-to-end connection of twoadjacent units combined. as shown in Fig. 4; and

Fig. 6 is a vertical sectional view taken on line 6-6 of Fig. 5 showingthe stabilizer mounted in a housing.

The torsion bar or strap member 10 preferably is made of stainless steelbecause this metal is suitably resilient, strong and durable. Othermetals having similar properties can, of course, be used. The particularshape and dimensions of the torsion bar will depend, in each case, uponthe particular lighting fixture in which it is installed. In theembodiment shown in the drawings the torsion bar 10 is made of a flatstrip of sheet metal. The strip is formed in a press, for example, tohave raised end portions 11 and 12, a raised central or middle portion13 and two depressed intermediate portions 14 and 15, respectively. Thedepressed portion 14, is formed between the raised end portion 11 andthe raised middle portion 13 and the other depressed portion 15 isformed between the other raised end portion 12 and the raised middleportion 13. A central hole 17 is cut through the middle portion 13 and aflat threaded pad or nut 18 is fastened to the under side of the middleportion by any suitable means, such as by spot welding, with aninternally threaded hole 19 of the pad or nut aligned with the hole 17,as best shown in Fig 3. Circular recesses 21 and22 are formed indepressed portions 14 and 15, respect-ively, equidistant from the centerof hole 17.

As best shown in Fig. 2, the torsion bar 10 is fastened inside ahorizontal base element or inverted channelshaped stabilizer 23 havingupper and lower surfaces as shown and with the raised middle portion 13projecting freely through a square opening or hole 24 cut in the middleof the top 26 of the stabilizer. The hole :24 is made larger than theportion 13 to avoid touching of the edges of the hole by the torsion bar10. Rivets 27 are shown passing through holes 28 in the stabilizer top26 and holes 29 in the torsion bar raised end portions 11 and 1-2,respectively, for attaching the torsion bar 10 to the under side of thestabilizer top '26, but it will be understood that the attachment can bemade by any other suitable fastening means such as spot welding,brazing, bolts, screws, etc., as desired. Leveling screws 31 and 32 arethreaded into internally threaded holes formed in the stabilizer top 26so that the screws can be made to engage in the recesses 21 and 22,respctively, in the top of torsion bar 10, as best shown in Fig. 2.

A vertical support or suspension tube is provided in the form of athreaded steel tubing stem 33 having a nut 34 (Fig. 2) threaded on thethreaded end 36 thereof. The threaded end 36 of the stem 33 is screwedinto the internally threaded hole 19 of the pad or nut 18 the desireddistance and a safety bushing or cap member 37 is tightly threaded ontothe protruding threaded end of the tubing stem 33 to engage against theunderside of pad 18. The nut 34 then is drawn tightly down onto the topof the exposed middle portion 13 of the torsion bar 10 to tightly securethe tubing stem 33 on the torsion bar.

The stabilizer channel 23 is then enclosed in a stabilizer housing 38which can be made up of two vertical side channels 39 and 40,forexample, or any suitable end cap construction to enclose thestabilizer therein. Each end of thelighting figtture. ispmvided withsuch an assembly of sta il zer}; to iqahar 9 tub tisste m. and. ate...

bilizer housing 38. The lamp housings 42 and 43 (Fig. 4) of the fixtureare mounted in spaced parallel arrangement etween wosuch a d assemb ieand -r nfc qedbr cross-member 44 fastened between the mid-portions;.gf;e. lamp ousings. T c ss-member!!! c e e as the housing for the ballast.

A lighting fixture consisting of a single unit is sus:- p ed y twotubing. st m 3 om a ce l .soth ele trical connectioniis-made throughanelect ric outlet box, by means known in the art. Any departure of theplane of the fixture from the horizontal is rapidly. and efficiently ore t dby. simp y. usi sa rew driver o-=t r ne or bothleveling serews '31;and-132 intothe stabilizer top Z 6 The leveling screws 31 and 32 thenare brought to bear s in tthe top of torsion bar 9. n ce sfil a 2spective y, wi h difi rent degreescfip e sureo oppos te i s t eaxisofthe ubings m 33i a hof. t e tw cases; The result of this actiorfistocause one side of the torsionbar 1!} to be depressed more than theother side thereof; as shown by dotted lines in Fig. 2. This produces atransyerse angle of tilt in the fixture to take care of any slope in theceiling transversely to the lighting fixture It also can be made tobalance or level the largest degrees of unbalance suchas may be causedby four heavy electricalfeed wires in one of the stabilizer housings orone of the side channels. If one end of the fixture is at a lower levelthan the other end, this deviation from a horizontal plane readily canbe corrected by turning one of the tubing sterns farther into the pad ornut 18 and, if desired, partially unscrewing. the tubing stem 33 at theother end of the fixture.

It willbe seen that a lighting fixture hung in this manner will bepermitted to sway or swing both longitudinally and transversely whencaused to do so by vibration or shock waves transmitted theretothroughtubing ste rns .3 3. The amplitudeof such swinging will, however,be keptrelatively, smallbecause of the resilient reaction in the torsionbar 10. As the amplitudeofthe swings tends will, crease, ,suchas, byresonance effects, the counteracting strains in the torsion bar act withincreased force against the swings to prevent successive increases inamplitude. In this manner, the energy of the vibration and shock Wavesis largely absorbed in the torsion bar and is not transmitted unabatedto the lighting fixture, proper. Fragilepartsand.components of thefmture are, therefore, ,efiectively protected from breakage and otherdam: age. Occupantsof the rooms. in which the lighting: fixtures aremounted are correspondingly protected from-injury and panicgwhichmay beinitiated; by fallingparts ofbroken light. fixtures duringan emergency.

:For continuous mounting of a plurality of-fixtures in end1to endrelationship, asindicated in Fig. 4, the proce dure. is similar to thatdescribed above for. a single fixture. One stabilizer 23. is. usedbetween two adjacent fixtures, as best shown in Fig. 5. The adjacent.fixtures are keyed .into the stabilizenas shown, and the resultingstabilizer and torsion bar assembly is housed inside a housing 38consisting of two vertical channels. 39 and 40 mounted on thestabilizer, as described above, in connection with the description of asingle fixture. The, leveling operations alsoare the same as thosedescribed above for a single fixture installation, as are the operationsof :the torsion bars in absorbing the energy, of shock and vibrationwaves and in. protecting the. lighting fixture from damage.

Although a specific embodiment of my invention has. beenfclescribed andillustrated above, it will be understood that other embodimentsof theinvention can be made, by the incorporation of changes or modificationswithin the skill of the. art and-without departing from the, spirit, ofthe invention. ll desire, therefore, to be afforded thefull scope of thefollowing claims.

I claim as my invention:.

1. In a lighting fixturehangenthe comhinatiomof:

4 a horizontal base element, havingan openlng'therein, a cl-hay nsaperaadlawer a member disposed adjacentto one of said surfaces inalignment with said opening, 1

said member being formed of resilient material, said member having endsrigidly secured to said one of said surfaces, and

having a pair of intermediate portions therebetween on each ecf a d Qpsusan pace said e of said surfaces, and

having a central'portion aligned with said opening and connecting saidintermediate'portions and being bent into said opening; and connectingmeans for at taching a vertical; support to. said centralportion of.said member.

2. A device as set forth in claim 1, having adjustment means between thebase element and the'member for varying the spacing therebetween.

. A ev c se for h. in l may ea ju tme the base elernent '4. A deviceasset forth in claim;l, in which the con:

opening therein adapted to receive; a threaded vertical support. 3

5. Adevice as set forth in claim l, in which the central por ion of hembe e n s.t uahm op ao ss mem e t pro id a aring. surf ce pac d: rom

theotherv of the surfaces of the base element.

6. A device as set forth'inclaim 1, in; which the memthan its width.

n. a l hting fix e a ger, e comb nat on of;

a or ontal. see eme h vine npe nd: 9w,e1';$ll1 'f' faces; and having anopening thereirn.

a strap member disposed adjacent to said lowersurface;

saidmemberbeing formedof resilient'metal,

said-.memberbeing relatively thin-,and having-alength and connectingsaidintermediate portionsandb'entup" V wardly through. said opening.to-. provide. a bearing. SDI.

face thereabove;

a pad element rigidlyv-secured to. said.- strap-member aligned said-Qcentral-portion thereof,-. and-haying a threaded opening therein; l

a vertical support having an externallythreadedscnd threaded. throughsaid threaded opening;

a cap. member threaded-on the end of saidsupport and engaging againstone side of said pad element; and

a nut on the threaded portion of said supportand engaging againstsaidbearing surface.

of threaded openingsis formed in said base element on each side of. theopening therein and aligned-'with-the. member, there being an adjustmentscrew.-:threaded through each of'said threaded openingsto.adiustablyengage .-an intermediate portion of the member, the memherbeing provided with a pair of; recesses-to receive the ends of saidadjustment screws.

9. In a lighting-fixture hanger, the combination of: a 1

a horizontal 1 base elementlhaving upper and] lower surfaces;

an elongated member disposed adjacent to one .of .said surfaces,

said. member. being formed of a resilientnmaterial, said member havinga. central portionadaptedto 75 .-.-.-.be connectcdltothe lower end-ofaverticahsuppgrt,

me ns. betwe heba el ent a ach of he. nt r-"1; e te po nso e m mbe t orpend nt y va yi the spacing between each of the intermediate portionsand,

' necting means includes a pad-element rigidly secured to, the centralportion of the member and having athreaded.

her is. relatively thin andhas a length substantially greater:

having a pair of intermediate, portions. -thcrebetween 8. A device asset forth in claim 1, in which a pair said member having opposite endsrigidly secured to said strap member having opposite ends rigidly 86-said one of said surfaces, and cured to said lower surface, and

having an intermediate portion on each side of said having at least oneintermediate portion between central portion which is spaced from saidone of said said ends and spaced from said lower surface; surfaces; 5connecting means associated with said strap member connecting meansassociated with said central portion and adapted to attach a verticalsupport to said member for attaching a vertical support to said member;and so that said support extends through said opening; and

adjustment means between said base element and said adjustment meansbetween said base element and said member for varying the spacingtherebetween. strap member for varying the spacing therebetween.

10. In a lighting fixture hanger, the combination of: 10 a horizontalbase element, having an opening therein References Cited in the file ofthis patent and having upper and lower surfaces; 7

an elongated strap member disposed adjacent to said UNITED STATESPATENTS lower surface in alignment with said opening, r 1,857,185Flaherty May 10, 1932 said strap member being formed of resilient metal,15 2,867,404 Ramsing Jan. 6, 1959

